1. Field of the Invention
The present invention relates to an electric multiple-valued register for electrically maintaining a multiple-valued digital signal, such as ternary value of (0, 1/2, 1), quaternary value of (0, 1/3, 2/3, 1) or quinternary value of (0, 1/4, 2/4, 3/4, 1), instead of a binary digital signal such that 1 digit is either 0 or 1. The present invention maintains a multiple-valued digital signal by inserting an element, having a stair shaped voltage-current characteristic, into a coupling circuit of a conventional flip-flop circuit. An industrially applicable field for applying the present invention is in different kinds of information processing apparatus such as multivalued computers. The present invention is particularly suitable for constructing a real time analog-digital mixed parallel distribution processor, such as a voice recognition processor. As an actual use, mention may be made of a quantization circuit with the aid of a step characteristic, a multivalued memory, a multivalued register, a multivalued loop memory, a multivalued pattern matching circuit, a voice recognition divide, a pattern recognition device, an associative memory device and the like.
2. Related Art Statement
A binary digital system using a flip-flop circuit as a conventional binary registering circuit has actively been developed by integrated circuit techniques, and in recent VLSI and ULSI development, a wiring amount within a chip is increased to occupy more than 70% thereof. Therefore, a multivalue computer is highly expected, and multiple-valued information processing, such as multivalued arithmetic operation and the like, has been studied.
A conventional study of multiple-valued logic was focused on algorithms, with the hardware based on binary digital system circuits. Therefore, a conversion of binary value into multiple value or multiple-valued operation circuit became complicated this cancelling the merit of the arrangement.
As a multiple-valued flip-flop circuit having a number of stable values, there is a flip-flop circuit having three stable values disclosed by Arango et al (IEEE Trans., EC-15, p. 661, 1966) or Tanaka et al (The Transactions of the Institute of Electronics and Communication Engineers, Vol. 52-C, No. 11, p. 667, 1969). These circuits materialize three stable values by using a plurality of source voltages, and in such a circuit, difficulty increases as multivalued numerals are increased to four-valued and five-valued. Hitherto, the flip-flop circuit depends upon the previous state, so that it has been constructed by considering its algorithm as a sequential logic circuit. It was difficult to understand that the value taken by the flip-flop circuit is increased to three-valued and four-valued when we are aware of sequential logic.
In other words, multiple-valued logic has been studied by substantially keeping pace with binary logic, but the time when a practical study is advanced is quite recent when internal wiring has occupied many portions within chip and micronization has reached the limit. Moreover, it is desired in future digital information processing to handle information of ambiguous form, such as in neural networks or voice networks having the same function as neural networks of human brains. In this case, even with uncertain information, it is necessary to call storaged information most closely related to the uncertain information. If there are multiple-valued registers and multiple-valued memories, information can be processed in a parallel dispersion manner with an analog sense. These circuits can be constructed with a multiple-valued flip-flop circuit having a registering function, and a compact multiple-valued flip-flop circuit is important.
Ternary and quaternary flip-flop circuits and logic circuits have variously been studied so far. However, a conventional binary flip-flop circuit functions as a sequential logic circuit element, but in case of more than quaternary states, the state setting of its algorithm becomes very complicated, and its merits are cancelled out. There was no breakthrough for improving multiple-valued flip-flop element having such information processing function that multivalues are simply held and stored.
At the developing age of post binary computers such as neural-net fuzzy logic, multiple-valued logic and the like, a compact multiple-valued registering circuit has become very important.
Arithmetic operations, such as addition, are possible with a simple analog circuit by materializing a circuit for merely placing multivalued values. It is possible to greatly contribute to putting multivalued computer to practical use by only materializing a circuit for setting and maintaining multivalued values as an electronic multiple-valued register.